The Secret Blueprint to Changing Your Domain Name Without Losing a Single Visitor

An important consideration for this step is your SSL certificate. You need to ensure it is active and valid for the new domain. On WordPress.com, SSL/HTTPS is included with every plan.
7. Update links in your database
After changing your domain, all WordPress page and menu links will switch automatically as well. However, you likely still have manually created links pointing to the old domain in posts, pages, and elsewhere.
The easiest way to update those is to replace them in your website’s database. WordPress has several plugin solutions for this, like Update URLs.